The information in this document was created from the devices in a
specific lab environment. All of the devices used in this document started with
a cleared (default) configuration. If your network is live, make sure that you
understand the potential impact of any command.

Cisco Unified Communications Manager 5.0 can be used to convert an SCCP
IP phone into a SIP IP phone using the Migrate Phones option
under Phones provided in the Bulk Administration. After you convert SCCP IP
phones to SIP IP phones, they fail to register with the Cisco Unified
Communications Manager 5.0 and display the Registration
rejected error message. The same IP phones successfully
register with the SCCP load.

The SIP IP phones fail to register because the auto-registration for
SIP is not enabled in Cisco Unified Communications Manager. The default Auto
Registration Phone Protocol is SCCP.

Complete these steps in order to enable auto-registration for SIP IP
phones in the Cisco Unified CallManager Administration page:

Login to the Cisco Unified CallManager Administration page with the
Username CCMAdministrator.

Choose System and click Enterprise
Parameters.

Change the Auto Registration Phone Protocol from SCCP to
SIP.

Click Save at the bottom of the Enterprise
Parameters Configuration page and restart all services in order for the
parameter change to take effect.

Note: If you have IP Phones with SIP Auto-Registration enabled and the
auto-registration fails, check if the IP Phones still run an older version of
SCCP. In this case, SCCP needs to be upgraded to the latest version and then
migrated to SIP. But if you try to upgrade the SCCP phone load first, this
fails because the phones are set to auto-register as SIP. So, register the
phones as SCCP first to upgrade the SCCP load, then change auto-registration
back to SIP, restart the Cisco Unified Communications Manager process, and
reboot the phones so that the phones are migrated to SIP.